Nebraska football coach Bo Pelini has unexpectedly come to know the challenges of starting a freshman quarterback. Veteran Taylor Martinez has missed the last six games after suffering a foot injury that's been called "debilitating."

In Martinez's absence, Pelini has turned to redshirt freshman Tommy Armstrong Jr. to take a majority of snaps. The results have been mixed as he's completed 61 of 115 passes for 802 yards with seven touchdowns and seven interceptions in seven games (six starts).

He's hit bumps in the road, including an interception, a fumble and a botched snap in a 41-28 loss to Michigan State last week. Pelini has addressed questions about Armstrong's performance the same way Penn State coach Bill O'Brien has about Christian Hackenberg.

"[We] still believe in Tommy, still think he's going to be a really good football player for us," Pelini said at his weekly news conference. "He's young. He's a freshman. He's not going to be perfect. He was disappointed yesterday, but once again because of that experience, it will make him better down the line."

Armstrong and Hackenberg will square off this weekend at Beaver Stadium in the Nittany Lions' home finale. Hackenberg is fighting through the "freshman wall," O'Brien said, with recent struggles and untimely turnovers, including a fumbled snap deep in Minnesota territory two weeks ago.

Pelini remained impressed with Hackenberg and said he's in good hands with O'Brien.

"I think he's a good player, and I think they've done a good job keeping it fairly simple for him," Pelini said. "The future is really bright with him, and obviously having Coach O'Brien there, he's obviously been around some pretty good quarterbacks and tutored some pretty good guys.

"I think he'll develop into a really good football player. He has all the tools, I mean, you see it. He has really good arm strength and can do a lot of things. The dude does a lot of things well."

Hackenberg earned his five-star recruiting status with prototypical size and a big arm, but he's surprised with his poise and ability to make clutch plays. But he's working to slow the game down and get on the same page with O'Brien, who said the two were only beginning to "speak the same language."

Hackenberg is one of just four true freshmen on the list of the NCAA's top 100 passers. It hasn't all been pretty, but he still ranks third in the Big Ten in passing (239.9 ypg) and has 14 touchdown passes to nine interceptions.

Hackenberg has worked to gain experience while steadying Penn State's offense. The learning curve gets a little tougher this week against a Cornhuskers defense that leads the Big Ten in sacks (36) and ranks fourth in interceptions (12).